The present invention relates to an active matrix type liquid crystal display using a horizontal electric field system.
As regards the display of information on a liquid crystal display (hereinafter, referred to as a LCD), an electric field is applied to liquid crystal (hereinafter, referred to as LC) molecules in a LC layer interposed between substrates to thereby change the direction of orientation of the LC molecules, and the display is obtained by a change in the optical quality of the LC layer resulting from the change in the direction of orientation of the LC molecules.
Particularly, an active matrix type LCD using active elements, which are represented by thin film transistor elements, has been employed as a display terminal of an OA apparatus having lower power consumption, by which the standard CRT will be replaced in terms of a response characteristic capable of coping with moving images at high precision and the like.
A conventional TN display system of the active matrix type LCD has a disadvantage in that it has a narrow visual field angle, which has posed a problem for the desired replacement of the standard CRT in terms of image quality.
On the other hand, a system (horizontal electric field system) for displaying information through the use of a change in double refraction properties of a LC by making the direction of an electric field to be applied to the LC, using comb-teeth electrodes, substantially parallel to the substrate surface, has been proposed, for example, in Japanese Patent Publication No. 63-21907 by "R. Kiefer, B. Weber, F. Windcheid and G. Baur, Proceedings of the Twelfth International Display Research Conference (Japan Display 192) pp. 547-550".
This horizontal electric field system has advantages, such as wider visual field angle, and lower loading capacity than the conventional TN system, and this technique offers hope as a full-fledged active matrix type LCD capable of replacing the standard CRT.